Sheet collecting mechanism



Oct. 10, 1957 I ERK 3,345,923

SHEET COLLECTING MECHANISM Filed April 25, 1965 5 Sheets-Sheet 1 Jnvenlor:

AMIR ERK,

Oct. 10, 1967 A. ERK 3,345,923

SHEET COLLECTING MECHANI SM Filed April 25, 1963 5 Sheets-Sheet 2' Fig.2

Jrn/emor:

AMIR ERK Oct. 10, 1967 K 3,345,923

' SHEET COLLECTING MECHANISM Filed'April 25, 1963 5 Sheets-Sheet Jn venfor:

AMIR ERK United States Patent E Claims. (Cl. 93-93) The invention relates to an apparatus for gathering sheets of paper or cardboard or foils or other products in leaf form, and for advancing the pack consisting of a predetermined number of sheets to stackers, the apparatus being equipped with :a gathering cylinder, a deflectorstripper and driven sling bands cooperating with the gathering cylinder. Hereby, the term deflector-stripper is used to designate the member in form of a switch tongue which leads the sheets on and off the collecting cylinder. p

The above-described apparatus have become well established on account of their low cost of construction as compared with other gathering devices for materials in leaf form, and they are generally used in tandem with a crosscutter so as to collect the sheets produced by the crosscutter and then advance them to stackers or other associated machines.

In these known apparatus, considerable difficulties are encountered, especially in the case of changes in operating speeds and in the number of sheets to be gathered each time. These difficulties consist first of all in the fact that, in spite of the special system for driving the sling bands, there is no assurance of a secure and perfect gathering of the sheets on the cylinder. Since the length of the sling bands that is in contact with the periphery of the cylinder varies with the number of sheets on the cylinder, and since there is a diiference in the amount of friction between the sling bands and the sheets on the one hand and between the sheets themselves on the other, a variable slippage between the bands and the cylinder is inevitable. The result is a shingling or overlapping of the sheets on the cylinder, which becomes particularly'evident in the case of high rotational speeds of the gathering cylinder. This causes the sheets to be damaged in the stacking step or already to be injured when the deflector-stripper switches to the stripping position, and it is a frequent cause of disturbances in operation.

In order to prevent the above-mentioned shingling, the diameter of the band driving roll has been selected in such a manner, on the basis of the average slippage between the bands and the cylinder as determined by practical experimentation, that an approximate equalization is achieved in gathering a particular number of sheets on the cylinder. However, when the numberof sheets per pack changes, or when the feeding of the sheets to' the gathering cylinder is irregular as in the case of gathering cylinders used in tandem with sorting systems, or when the friction characteristics of the sheets vary, it is impossible to equalize the slippage by means of the size of the band driving roll.

Another difiiculty encountered with the system described lies in the control of the deflector-stripper. Hitherto a cam has been used to shift it into the stripping position, the said cam being driven by the. gathering cylinder through a gear train at a rotatory speed per unit of time that varies according to the number of sheets to be gathered. When the number of sheets is changed, then, one or more of the change gears of the transmission must be replaced accordingly, and the circumferential length of the cam must also be changed, which is usually accom'-' plished by replacing the cam. Consequently, these deflector-stripper controlling or operating systems are expensive on account of the change-gear transmission 3,345,923 Patented Oct. 10, 1967 which they require, and they necessitate interruptions in operation whenever the number of sheets per pack is changed. Furthermore, the prior-art operating systems are entirely unusable when the feed of sheets to the gathering cylinder is irregular, because then they advance packs containing different numbers of sheets, and sometimes they even put out single sheets, resulting in considerable difiiculties in the stacking operation.

It is a principal object of the invention to prevent the above-mentioned difliculties in gathering and stacking sheets, and to improve the known apparatus so that the sheets will be gathered on the cylinder without shingling, regardless of the number of sheets to be gathered per pack, even in the case of irregular sheet feed, and so that, furthermore, it will be possible to operate the deflectorstripper according to the number of sheets per pack desired in each case, even when the sheet feed is irregular, at the same time eliminating the expenses hitherto required for thetransmission and the change gears.

To solve the above-mentioned problems, the invention provides for the adjustable driving of the sling bands and provides a system for controlling the deflector-stripper, wherein two switching devices cooperate, one of which permits the deflector-stripper to be switched into the stripping position only over that peripheral portion of the cylinder that is not covered by the sheets, while the other switching apparatus is controlled by an adjustable counting mechanism and releases the deflector-stripper only after a certain number of sheets have been collected on the gathering cylinder.

The controllability of the sling band drive then makes it possible without difliculty to compensate for the slippage that occurs, which diifers according to the conditions of operation. It is possible to provide a separate drive for the sling bands; expediently, however, an intermediate gear that meshes with the peripheral gear of the gathering cylinder serves to drive the bands, the said intermediate gear turning the band driving roll through an infinitely variable speed transmission.

Compensation for the slippage by adjustment of the sling band drive can be performed manually. It is advantageous, however, to provide a preferably photoelectric sensing device to detect the sheet displacement on the gathering cylinder and to automatically regulate the speed change transmission accordingly. The transmission in this case needs to be designed only for a transmission ratio range of about 1 to 1.2 as the slippage never exceeds 20% The deflector-stripper controlling system also provided by the invention assures that the deflector-stripper always operates in the sheet rhythm and switches into the stripping position only when the cylinder has assumed a predetermined position.

Systems operating directly in tandem with a crosscutter from which each sheet runs to the gathering cylinder can be equipped with a counting mechanism which is oper atively connected with the gathering cylinder and performs one counting step with each revolution of the cylinder. However, according to another feature of the invention, the counting mechanism can instead be connected with a preferably photoelectric system for the registration of the sheets fed to the gathering cylinder. This latter improvement finds application preferably whenever it is possible that the feeding of the sheets to the gathering cylinder may be irregular.

Counting mechanisms of the prior art are used, which are adjustable in such a manner that the disengagement of a pawl or the deenergizing of a holding magnet which they produce is performed in each case after a certain variable number of stepping or counting operations.

Experience has shown that it is of advantage to equip the apparatus with a combined mechanical and electrical or mechanical and electromagnetic operating or tripping device for the operation or release of the deflector-stripper. To this end, an embodiment of the invention provides a cam which rotates with the gathering cylinder and which cooperates with a cam follower mounted at one end of a lever which is mechanically connected with the deflector-stripper and is held by an electromagnet or by a pawl, against the urging of a spring, in a position wherein it keeps the follower and cam out of contact, the counting mechanism being designed to trip the pawl or deenergize the magnet only when the cam lobe is pre sented to the cam follower.

To operate the counting mechanism, the gathering cylinder can cooperate with an impulse generator, preferably an inductive impulse generator, whose impulses are fed, through an amplifier if desired, to the counting mechanism.

Instead of a partially mechanical and partially electrical operation of the system that controls the deflectorstripper, it is possible according to a further embodiment of the invention to have an all-electrical system by using an electromagnet to switch the deflector-stripper into the stripping position, pairs of contacts being provided in the circuit of the said electromagnet which are operated according to the position of the gathering cylinder, the said pairs of contacts being disposed in series with an additional pair of contacts controlled by the counting mechanism.

Further details of the invention will become apparent from the description of the embodiment represented in the drawings.

The drawings show a number of gathering devices constructed according to the invention.

FIG. 1 schematically represents a novel apparatus for the gathering of sheets, wherein the system that controls the deflector-stripper is operated mechanically in part and in part electromagnetically.

FIG. 2 shows an embodiment of the system that differs from the embodiment in FIG. 1.

FIG. 3 schematically illustrates an electrical and electromagnetic control for holding and releasing the deflector-stripper.

FIG. 4 shows a detail of the apparatus, and

FIG. 5 is an exploded view of the cam means used.

In the drawings, 1 designates the shaft of the gathering cylinder 2. A deflector-stripper 3 cooperates with the gathering cylinder, the said deflector-stripper being fastened at a pivot point 4 to a stationary part of the apparatus in such a manner that its fingers 5 directed towards the gathering cylinder can be moved away from the gathering cylinder (to a position in which it deflects the sheets onto the cylinder), or can be moved into the stripping position in which they enter into circumferential grooves created in the gathering cylinder. In all the drawings, 6 designates a counting mechanism having electrical contacts which momentarily open or close after a predetermined number of counting steps.

In FIGS. 1 and 2, the conveyors 7 serving to carry the sheets to the gathering cylinder are represented schematically. In these embodiments, these conveyors are disposed in tandem with crosscutters 8, to which material is fed in continuous sheet form by other conveyors which are not shown in the drawings, the said material being cut into sheets by crosscutter 8 and then passing over conveyor 7 to gathering cylinder 2. The gathering cylinder is equipped with sling bands 9, which are guided around guide rollers 10, and a driving roll 11. The power for the operation of driving roll 11 is in this case derived from the gathering cylinder 2, an intermediate gear 12 meshing with the peripheral gear 2a of cylinder 2, and powering the driving roll 11 through an infinitely variable speed change transmission 13, which may consist of truncated 4 cones 13a, 13b and a belt 13c adjusted by arm 13d (FIG. 4).

The speed change transmission 13 is connected in the embodiments in FIGS. 1 and 2, as indicated by a broken line, with a photoelectric sensing device 14, which serves to determine the sheet displacement on the gathering cylinder and serves for the automatic control of transmission 13 through a servo-motor not shown in the drawing; when the slippage between the sling bands 9 and gathering cylinder 2 varies, the transmission ratio of transmission 13 is varied accordingly. As the sheets are always placed on the gathering cylinder with their trailing ends in superposed position and always take up the same position on the periphery of the cylinder, independently of their length, the photoelectric cell 14 can be directed onto said area of the periphery so as to adjust the transmission in the one or other direction when the sheet ends are displaced due to shingling. This is also a well known arrangement which is conventional whenever sheets are kept in alignment or register by means of photoelectric devices, and need, therefore, not to be set forth in more detail.

In FIGS. 1 and 2, the deflector-stripper 3 is connected through a pull rod 15 to a lever 16 which is attached :at pivot point 17 to a stationary part of the apparatus. At the end of lever 16 next to the gathering cylinder there is mounted a cam follower 18 which cooperates with a cam 19 rotating synchronously with the gathering cylinder. The end of lever 16 opposite cam follower 18 is under the influence of a compression spring 20, and, in the embodiment in FIG. 1, it is furthermore attached to the armature 21 of a holding electromagnet 22. Electromagnet 22 is connected through switch 23 with the counting mechanism 6, which in turn is connected with a photoelectric system 24 for the registration of the sheets carried to the gathering cylinder.

The manner of operation of the system controlling the deflector-stripper 3 is the following:

When the deflector-stripper is in the deflecting position shown in FIG. 1, electromagnet 22 is energized so that lever 16 draws cam follower 18 out of contact with cam 19 against the efiect of spring 20. When the number of sheets gathered on cylinder 2 and registered by the photoelectric system 24 arrives at the total preset in counting mechanism 6, the latter, by the operation of switch 23, causes electromagnet 22 to become de-energized, so that cam follower 18 is brought by the effect of spring 20 into contact with cam 19. This makes it possible for the deflector-stripper to come into the stripping position as soon as cam follower 18 rolls ofl" cam lobe 25. That is to say, the impulses emitted by the photoelectric sensing system are fed to counting mechanism 6 through a delay system installed, if desired, in the counting mechanism, in such a manner that the de-energizing of electromagnet 22 or the contact between cam follower 18 and cam 19 takes place precisely within the time in which cam lob 25 is presented to cam follower 18, cam lobe 25 being disposed in relation to gathering cylinder 1 in such a manner that, when the cam follower rolls off of the cam lobe, the portion of the periphery of the cylinder that is not covered by the sheets is presented to the deflector stripper.

After the shifting of deflector-stripper lever 3 into the stripping position, cam follower 18 remains in contact with the cam for almost one full revolution of the latter, and during this time the deflector-stripper remains in the stripping position. Switch 23 needs to open for only a very brief time to produce this effect, because once cam follower 18 contacts the cam, electromagnet 22 is incapable by itself of overcoming the effect of spring 20, on account of the slight pulling force it has over the great air gap created between the magnet and the armature. Not until cam follower 18 has run back up onto cam lobe 25 can lever 16 swing back and, by means of pull rod 15, return deflector-stripper 3 to the deflecting positon.

To make it possible to vary the length of cam lobe 25, it is expedient to provide two cam disks 19 having lobes 25 disposed ofiset from one another, which can be rotated against one another on shaft 1 and can be locked in the position desired (FIG. 5).

The collected packs of sheets are fed 'by a conveyor arranged parallel to the deflector-stripper onto a conventional stacker platform which can be lowered as the stacking progresses and may be vibrated to assist the registering of the sheets. The present invention is not concerned with details of the stacker, which may be of conventional construction and is, therefore, not shown in the drawings.

In the embodiment represented in FIG. 2, which is substantially the same as the one in FIG. 1, instead of the electromagnet 22 cooperating with armature 21, a solenoid device 26 is provided, which is equipped with a pawl 27 which is held inthe engaged position by the effect of a spring 28. 'In this case, solenoid 26 is not energized, i.e., switch 23, which is in series with it, is open, when the deflector-stripper is in the deflecting position. When the counting mechanism has been preset to the desired number of sheets, and the impulses emitted by the photoelectric system 24 reach a total corresponding to that number, switch 23 is momentarily closed (rather than opened as in FIG. 1), so that solenoid 26 is energized and pulls pawl 27 out of engagement. The cam follower lever 16 thus released now performs, along with the other parts associated with it, the same movements as described in the case of the embodiment of FIG. 1 when magnet 22 was de-energized.

Instead of the photoelectric sensing device 24, which is used particularly when the feeding of the sheets is irregular, counting mechanism 6 can be connected, if the crosscutters and gathering cylinders are coupled directly together, with an impulse generator which causes one count to be registered in the counting mechanism upon each revolution of the cylinder. This impulse generator is represented schematically in FIG. 2 and is designated by the number 29. It can :be designed as an inductive transducer and can cooperate with an armature disposed adjustably on the periphery of the gathering cylinder, so that the impulses can be coordinated with the position of the gathering cylinder.

In FIG. 3, an electrically operated system is shown in which, for the sake of simplicity, the conveyors and the sling bands and all other parts not necessary to the operation of the deflector-stripper 3 are omitted from the drawing. In the embodiment in FIG. 3, a solid conductive metal ring 31 is placed on shaft 1 of the gathering cylinder, with an insulating ring 30* between them, the said metal ring being connected through a brush 32 to one pole of a voltage source 33. Shaft 1 also bears insulating disks 34 and 36 which bear conductive segments 35 and 35a. Brushes slide on the circumferences of the insulating disks 34 and 36, the said brushes being connected by conductors 38 and 39 to a relay 37 and a switch 41, respectively. Conductor 38 is connected through relay 37, which operates the deflector-stripper 3, and through a switch 40, which is controlled by the counting mechanism 40, to one pole of the voltage source 33. Relay 37 does not respond upon each rotation of the gathering cylinder, but instead can respond only when switch 40, which is in series with it, is closed by the counting mechanism 6 when the desired number of sheets has been gathered on the gathering cylinder.

In the embodiment in FIG. 3, the counting mechanism is coupled with shaft 1 of the gathering cylinder, so that, after a certain number of revolutions of the gathering cylinder, depending on how it is set, it causes switch 40 to close, the impulse that closes it being so timed that it closes just when the brush associated with conductor 38 comes into contact with segment 35.

When relay 37 responds, it shifts the deflector-stripper into the stripping position, while simultaneously operating the catch and pawl mechanism 43, whose catch is formed by the prolongation 42 of the deflector-stripper operating rod, and whose pawl is created on the prolongation of the plunger of a solenoid device 45. The winding of solenoid device 45 is connected at one end to the negative pole of voltage source 33 and at the other end to a working contact of switch 41, so that, when segment 35a is contacted by the brush to which conductor 39 is attached, and when switch 41 is closed, the circuit of the said winding is closed. When solenoid 45 is energized, it disengages the catch and pawl mechanism 43 against the elfect of spring 44, and thus causes deflector-stripper 3 to return to the deflecting position under the effect of compression spring 20.

The purpose of switch 41 is to prevent solenoid 45 from being energized upon each revolution of the gathering cylinder, because it can be energized only when the deflector-stripper is in the stripping position, since only then is switch 41 closed.

On account of the mechanical coupling between shaft 1 of the gathering cylinder and the counting mechanism 6, the embodiment in FIG. 3 is suitable only for installation directly in tandem with a crosscutter, since the operation of the deflector-stripper is coordinated only with the rotation of the gathering cylinder.

I claim:

1. Apparatus for gathering sheets into packs of a predetermined number of sheets and advancing them to stackers, comprising a gathering cylinder having a periphery which is larger than the length of the sheets to be collected, means to feed the sheets onto the cylinder to form packs thereon covering part of the'cylinder periphery and leaving part thereof uncovered, sling bands cooperating with and partially encircling said cylinder, means to drive said sling bands, means to control the speed of said bands so as to compensate for slippage of said sheets and to ensure that said part of the cylinder periphery remains uncovered by sheets, a deflector-stripper adapted to operate in a raised or lowered position being positioned above the cylinder and adjacent to the outlet of said feed means, said deflector-stripper in the raised position adapted to deflect said sheets to a position 'between the sling bands and the cylinder, and in the lowered position to strip said packs from the cylinder, and means to control the deflector-stripper to position it in either the raised or lowered position, said control means comprising, in cooperation, (a) an adjustable counting mechanism and a first switching device which is operated by said counting mechanism and releases the deflector-stripper into stripping position after a predetermined number of pack-forming sheets has been collected on the cylinder and counted, and (b) an adjustable control device and a second switching device which is operated by said control device and allows actuation of said stripper-deflector by said first switching device only when the stripper-deflector registers with said uncovered part of the cylinder.

2. Apparatus as set forth in claim 1 wherein the means to drive the sling bands comprises a peripheral gear on the cylinder, a second gear meshing with said peripheral gear, an infinitely variable speed drive transmission connected to said second gear, and a drivng roll driven by said transmission.

3. Apparatus as set forth in claim 1 wherein said counting mechanism is operatively connected with the gathering cylinder and performs one count upon each revolution of the cylinder.

4. Apparatus as set forth in claim 3 wherein the means for controlling the deflector-stripper comprises an impulse generator consisting of an inductive transducer which actuates the adjustable counting mechanism.

5. Apparatus as set forth in claim 1 wherein the means for moving the deflector-stripper to the stripping position comprises cam means revolving with the gathering cylinder and cooperating with a cam follower disposed at one 7 end of a lever which is mechanically connected to the deflector-stripper and is held by holding means against the efiect of a spring in a position in which it keeps the cam follower and the cam out of contact with one another, the counting mechanism releasing said holding means when the cam lobe is presented to the cam follower.

6. Apparatus as set forth in claim 5 wherein said holding means is an electromagnet and wherein said cam has a lobe which serves to return the deflector-stripper to the deflecting position in which it is held by said electromagnet until an impulse is emitted by the counting mechanism.

7. Apparatus as set forth in claim 5 wherein said cam means comprises two cam discs having lobes disposed ottset from one another, said cam discs being rotatable against each other to adjust the total length of the lobes.

8. Apparatus as claimed in claim 1 wherein said adjustable control device comprises an electromagnet for moving the deflector-stripper into the stripping position, an electric circuit for actuating said electromagnet, and switch contacts in said circuit operated in coordination with the position of the gathering cylinder, said switch contacts being disposed in series with an additional contact of said first switching device operated by said counting mechanism.

9. Apparatus as set forth in claim 8 wherein at least one of said switching contacts, which is operated in coordination with the position of the gathering cylinder, has a switching disk rotating synchronously with the gathering cylinder, which is equipped with contact segments.

10. Apparatus as set forth in claim 8 wherein said contact segments are adjustable.

References Cited UNITED STATES PATENTS 1,545,916 7/ 1925 Maxson. 2,278,188 3/1942 Bamford et al 270-6O 2,424,093 7/1947 Hatred 93-93.3

TRAVIS S. MCGEHEE, Primary Examiner.

FRANK E. BAILEY, Examiner. 

1. APPARATUS FOR GATHERING SHEETS INTO PACKS OF A PREDETERMINED NUMBER OF SHEETS AND ADVANCING THEM TO STACKERS, COMPRISING A GATHERING CYLINDER HAVING A PERIPHERY WHICH IS LARGER THAN THE LENGTH OF THE SHEETS TO BE COLLECTED, MEANS TO FEED THE SHEETS ONTO THE CYLINDER TO FORM PACKS THEREON COVERING PART OF THE CYLINDER PERIPHERY AND LEAVING PART THEREOF UNCOVERED SLING BANDS COOPERATING WITH ANE PARTIALLY ENCIRCLING SAID CYLINDER, MEANS TO DRIVE SAID SLING BANDS, MEANS TO CONTROL THE SPEED OF SAID BANDS SO AS TO COMPENSATE FOR SLIPPAGE OF SAID SHEETS AND TO ENSURE THAT SAID PART OF THE CYLINDER PERIPHERY REMAINS UNCOVERED BY SHEETS, A DEFLECTOR-STRIPPER ADAPTED TO OPERATE IN A RAISED OR LOWERED POSITION BEING POSITIONED ABOVE THE CYLINDER AND ADJACENT TO THE OUTLET OF SAID FEED MEANS, SAID DEFLECTOR-STRIPPER IN THE RAISED POSITION ADAPTED TO DEFLECT SAID SHEETS TO A POSITION BETWEEN THE SLING BANDS AND THE CYLINDER, AND IN THE LOWERED POSITION TO STRIP SAID PACKS FROM THE CYLINDER, AND MEANS TO CONTROL THE DEFLECTOR-STRIPPER TO POSITION IT IN EITHER THE RAISED OR LOWERED 